<?
ob_start("ob_gzhandler");
require_once("../include/bittorrent.php");
require_once("../include/benc.php");

function err($msg)
{
	benc_resp(array("failure reason" => array(type => "string", value => $msg)));
	exit();
}

function benc_resp($d)
{
	benc_resp_raw(benc(array(type => "dictionary", value => $d)));
}

function benc_resp_raw($x)
{
	header("Content-Type: text/plain");
	header("Pragma: no-cache");
	print($x);
}

function portblacklisted($port)
{
	// direct connect
	if ($port >= 411 && $port <= 413) return true;

	// bittorrent
	if ($port >= 6881 && $port <= 6889) return true;

	// kazaa
	if ($port == 1214) return true;

	// gnutella
	if ($port >= 6346 && $port <= 6347) return true;

	// emule
	if ($port == 4662) return true;

	// winmx
	if ($port == 6699) return true;

	return false;
}

foreach (array("passkey","info_hash","peer_id","ip","event") as $x)
	$GLOBALS[$x] = "" . $_GET[$x];

foreach (array("port","downloaded","uploaded","left") as $x)
	$GLOBALS[$x] = 0 + $_GET[$x];

if (strpos($passkey, "?")) 
{
	$tmp = substr($passkey, strpos($passkey, "?"));
	$passkey = substr($passkey, 0, strpos($passkey, "?"));
	$tmpname = substr($tmp, 1, strpos($tmp, "=")-1);
	$tmpvalue = substr($tmp, strpos($tmp, "=")+1);
	$GLOBALS[$tmpname] = $tmpvalue;
}

foreach (array("passkey","info_hash","peer_id","port","downloaded","uploaded","left") as $x)
	if (!isset($x)) 
		err("Missing key: $x");

foreach (array("info_hash","peer_id") as $x)
	if (strlen($GLOBALS[$x]) != 20) 
		err("Invalid $x (" . strlen($GLOBALS[$x]) . " - " . urlencode($GLOBALS[$x]) . ")");

$ip = getip(); 

$rsize = 50;
foreach(array("num want", "numwant", "num_want") as $k)
{
	if (isset($_GET[$k]))
	{
		$rsize = 0 + $_GET[$k];
		break;
	}
}

$agent = $_SERVER["HTTP_USER_AGENT"];
// Deny access made with a browser...
if (ereg("^Mozilla\\/", $agent) || ereg("^Opera\\/", $agent) || ereg("^Links ", $agent) || ereg("^Lynx\\/", $agent))
	err("Invalid user agent");

if (!$port || $port > 0xffff)
	err("Invalid port");

if (!isset($event))
	$event = "";

$seeder = ($left == 0) ? "yes" : "no";

dbconn(false);

$valid = @mysql_fetch_row(@mysql_query("SELECT COUNT(*) FROM users WHERE enabled='yes' AND passkey=" . sqlesc($passkey)));
if ($valid[0] != 1) 
	err("Invalid passkey! Please redownload the .torrent from $SITEURL");

$res = mysql_query("SELECT torrents.id AS id, banned, seeders + leechers AS numpeers, UNIX_TIMESTAMP(added) AS ts, section FROM torrents LEFT JOIN categories ON category = categories.id WHERE " . hash_where("info_hash", $info_hash)) or err("1: ".mysql_error());
if (!$res)
	err("Torrent query error, contact staff!");
else if (mysql_num_rows($res) < 1)
	err("Torrent not registered with this tracker");
else
	$torrent = mysql_fetch_assoc($res);
mysql_free_result($res);

$torrentid = $torrent["id"];

$fields = "seeder, peer_id, ip, port, uploaded, downloaded, userid, UNIX_TIMESTAMP(last_action) as lastaction";

$numpeers = $torrent["numpeers"];
$limit = "";
if ($numpeers > $rsize)
	$limit = "ORDER BY RAND() LIMIT $rsize";
$res = mysql_query("SELECT $fields FROM peers WHERE torrent = $torrentid AND connectable = 'yes' $limit") or err("2: ".mysql_error());

$resp = "d" . benc_str("interval") . "i" . $announce_interval . "e" . benc_str("private") . "i1e" . benc_str("peers") . "l";
unset($self);
while ($row = mysql_fetch_assoc($res))
{
	$row["peer_id"] = hash_pad($row["peer_id"]);

	if ($row["peer_id"] === $peer_id)
	{
		$userid = $row["userid"];
		$self = $row;
		continue;
	}

	$resp .= "d" .
		benc_str("ip") . benc_str($row["ip"]) .
		benc_str("peer id") . benc_str($row["peer_id"]) .
		benc_str("port") . "i" . $row["port"] . "e" .
		"e";
}

$resp .= "ee";

$selfwhere = "torrent = $torrentid AND " . hash_where("passkey", $passkey) . " AND " . hash_where("peer_id", $peer_id);

if (!isset($self))
{
	$res = mysql_query("SELECT $fields FROM peers WHERE $selfwhere") or err("3: ".mysql_error());
	$row = mysql_fetch_assoc($res);
	if ($row)
	{
		$userid = $row["userid"];
		$self = $row;
	}
}

//// Up/down stats ////////////////////////////////////////////////////////////

if (!isset($self))
{
	$valid = @mysql_fetch_row(@mysql_query("SELECT COUNT(*) FROM peers WHERE torrent=$torrentid AND passkey=" . sqlesc($passkey)));
	if ($valid[0] >= 2 && $seeder == 'no') 
		err("Connection limit exceeded! You may only leech from two locations at a time.");
	if ($valid[0] >= 3 && $seeder == 'yes') 
		err("Connection limit exceeded!");

	$rz = mysql_query("SELECT id, uploaded, downloaded, class, parked FROM users WHERE passkey=".sqlesc($passkey)." AND enabled = 'yes' ORDER BY last_access DESC LIMIT 1") or err("Tracker error 2");

	if (mysql_num_rows($rz) == 0)
		err("Invalid passkey! Please redownload the .torrent from $SITEURL"); 

	$az = mysql_fetch_assoc($rz);
	$userid = $az["id"];

//	if ($left > 0 && $az["class"] < UC_VIP)
	if ($az["class"] < UC_VIP)
	{
		$gigs = $az["uploaded"] / (1024*1024*1024);
		$elapsed = floor((time() - $torrent["ts"]) / 3600);
		$ratio = (($az["downloaded"] > 0) ? ($az["uploaded"] / $az["downloaded"]) : 1);
		if ($ratio < 0.5 || $gigs < 5) $wait = 0;
		elseif ($ratio < 0.65 || $gigs < 6.5) $wait = 0;
		elseif ($ratio < 0.8 || $gigs < 8) $wait = 0;
		elseif ($ratio < 0.95 || $gigs < 9.5) $wait = 0;
		else $wait = 0;
		if ($elapsed < $wait)
			err("Not authorized (" . ($wait - $elapsed) . "h) - READ THE FAQ!");
	}
}
else
{
	$upthis = max(0, $uploaded - $self["uploaded"]);
	$downthis = (2 == $torrent['section']) ? 0 : max(0, $downloaded - $self["downloaded"]);
	$period = time() - $self["lastaction"];

	if ($period)
	{
		if (($upthis / $period) > 12500000)
			write_admin_log("cheated their upload stats by uploading " . bytesize($upthis) . " in $period seconds", $userid);
	}
	else
	{
		if ($upthis > 12500000)
			write_admin_log("cheated their upload stats by uploading " . bytesize($upthis) . " in $period seconds", $userid);
	}

	if ($self["seeder"] == "yes")
	{
		mysql_query("UPDATE users SET uploaded = uploaded + $upthis, downloaded = downloaded + $downthis, seedtime = seedtime + $period WHERE id=$userid") or err("Tracker error 3");
	}
	else if ($upthis > 0 || $downthis > 0)
	{
		mysql_query("UPDATE users SET uploaded = uploaded + $upthis, downloaded = downloaded + $downthis WHERE id=$userid") or err("Tracker error 3");
	}
}

///////////////////////////////////////////////////////////////////////////////

$updateset = array();

if ($event == "stopped")
{
	if (isset($self))
	{
		mysql_query("DELETE FROM peers WHERE $selfwhere") or err("4: ".mysql_error());
		if (mysql_affected_rows())
		{
			if ($self["seeder"] == "yes")
				$updateset[] = "seeders = seeders - 1";
			else
				$updateset[] = "leechers = leechers - 1";
		}
	}
}
else
{
	if ($event == "completed")
	{
		$res = mysql_query("SELECT torrentid, userid FROM snatched WHERE torrentid=$torrentid AND userid=$userid");
		if (!mysql_num_rows($res))
		{
			$updateset[] = "times_completed = times_completed + 1";
			mysql_query("INSERT INTO snatched (added,torrentid,userid) VALUES (NOW(),$torrentid,$userid)");
		}
	}
	if (isset($self))
	{
		mysql_query("UPDATE peers SET uploaded = $uploaded, downloaded = $downloaded, to_go = $left, last_action = NOW(), seeder = '$seeder'"
			. ($seeder == "yes" && $self["seeder"] != $seeder ? ", finishedat = " . time() : "") . " WHERE $selfwhere") or err("5: ".mysql_error());
		if (mysql_affected_rows() && $self["seeder"] != $seeder)
		{
			if ($seeder == "yes")
			{
				$updateset[] = "seeders = seeders + 1";
				$updateset[] = "leechers = leechers - 1";
			}
			else
			{
				$updateset[] = "seeders = seeders - 1";
				$updateset[] = "leechers = leechers + 1";
			}
		}
	}
	else
	{
		if ($az["parked"] == "yes")
		err("Not allowed. Your account is parked!");

		if (portblacklisted($port))
			err("Port $port is blacklisted.");
		else
		{
//			$sockres = @fsockopen($ip, $port, $errno, $errstr, 5);
//			if (!$sockres)
//				$connectable = "no";
//			else
//			{
				$connectable = "yes";
//				@fclose($sockres);
//			}
		}

		$ret = mysql_query("INSERT INTO peers (connectable, torrent, peer_id, ip, port, uploaded, downloaded, to_go, started, last_action, seeder, userid, agent, " . 
		"uploadoffset, downloadoffset, passkey) VALUES ('$connectable', $torrentid, " . sqlesc($peer_id) . ", " . sqlesc($ip) . ", $port, $uploaded, $downloaded, " . 
		"$left, NOW(), NOW(), '$seeder', $userid, " . sqlesc($agent) . ", $uploaded, $downloaded, " . sqlesc($passkey) . ")") or err("6: ".mysql_error());

		if ($ret)
		{
			if ($seeder == "yes")
				$updateset[] = "seeders = seeders + 1";
			else
				$updateset[] = "leechers = leechers + 1";
		}
	}
}

if ($seeder == "yes")
{
	if ($torrent["banned"] != "yes")
		$updateset[] = "visible = 'yes'";
	$updateset[] = "last_action = NOW()";
}

if (count($updateset))
	mysql_query("UPDATE torrents SET " . join(",", $updateset) . " WHERE id = $torrentid") or err("7: ".mysql_error());

benc_resp_raw($resp);

?>
